Randomized controlled trials (RCTs) are considered the highest level of evidence to establish causal associations in clinical research. As the complexity of research questions has increased, new methods have appeared, and RCT designs have become more complex.(1) Hence, it is important to appraise the quality of the design using adequate tools and checklists for these trials. This article describes some of the most popular tools and checklists for assessing the risk of bias in publications reporting randomized trials results.
Cochrane risk-of-bias tool for randomized trials (RoB 2.0)
The ROB 2.0 tool is recommended for evaluating the risk of bias in publications presenting randomized trial results in systematic reviews. This tool is organized into specific domains of bias, each addressing different aspects of trial design, conduct, and reporting. Within each domain, a series of ‘signalling questions’ gather information about trial features relevant to the risk of bias. Based on these answers, an algorithm generates a proposed judgment about the risk of bias for each domain. The judgments can be classified as ‘Low’ or ‘High’ risk of bias or as having ‘Some concerns.'(2)
Reference: Risk of bias tools – RoB 2 tool (google.com)
CASP Randomized Controlled Trial Appraisal Tool
The CASP checklist offers a structured approach for appraising publications of RCTs.(3) It helps researchers systematically evaluate the validity, results, and relevance of trials, ensuring that critical aspects of the study design are explored.
Reference: Microsoft Word – CASP RCT Checklist 11 qus [RB1 EI amendments 16_9_2020].docx (casp-uk.net)
Jadad Scale
The Jadad Scale is designed to assess the quality of RCT publications, focusing on three core elements: random assignment, blinding, and the flow of participants through the trial. It provides a simple numerical score informing meta-analyses and systematic reviews and identifying high-quality studies that can be used to inform clinical practice.(4)
Centre for Evidence-Based Medicine (CEBM) – RCT Checklist
The CEBM RCT checklist is another critical appraisal tool designed to evaluate RCT publications. It covers essential aspects such as randomization, blinding, follow-up, and controlling confounding variables. It appraises the reliability, importance and applicability of clinical evidence.(5)
Reference: RCT.pdf (cebm.net)
Joanna Briggs Institute (JBI) Checklist
The JBI checklist is a comprehensive tool for critically appraising RCT publications. It includes criteria for evaluating the trial design, conduct, and analysis, ensuring that all relevant factors are considered.(6) The checklist is part of JBI’s suite of evidence-based practice resources, widely used in healthcare research.
Reference: JBI_Checklist_for_RCTs_archive_2020.docx (live.com)
Scottish Intercollegiate Guidelines Network (SIGN)
These guidelines provide a straightforward system for critically appraising RCT publications. Its methodology emphasizes assessing internal and external validity by identifying key factors such as bias and confounding. SIGN uses tailored checklists to evaluate RCTs, grading evidence strength on a scale from ‘++’ to ‘–’ and classifying recommendations from ‘A’ to ‘D’.(7)
Reference: checklist_for_controlled_trials.doc (live.com)
NHLBI Study Quality Assessment of Controlled Intervention Studies
This tool evaluates publications of RCTs by addressing key study design, conduct, and reporting aspects. It includes criteria such as adequacy of randomization, allocation concealment, blinding, baseline similarity, dropout rates, adherence to protocols, outcome assessment, power calculation, prespecified outcomes, and intention-to-treat analysis. Each criterion is assessed with specific questions to identify potential bias, and studies are rated as ‘Good,’ ‘Fair,’ or ‘Poor’ based on the overall risk of bias.(8)
Reference: Study Quality Assessment Tools | NHLBI, NIH
Conclusion
The tools presented above provide structured and systematic approaches for evaluating RCT publications of RCTs. These tools help the researchers to critically evaluate the methodological approach and risk of bias in publications reporting on results of RCTs, thus promoting more reliable health outcomes.
References
- Zabor EC, Kaizer AM, Hobbs BP. Randomized Controlled Trials. Chest. 2020;158(1s):S79-s87.
- Cochrane Methods. Bias. RoB 2: A revised Cochrane risk-of-bias tool for randomized trials. 2024. Available from: https://methods.cochrane.org/bias/resources/rob-2-revised-cochrane-risk-bias-tool-randomized-trials . Last accessed on: 07 August 2024.
- UNC. Systematic Reviews: Step 6: Assess Quality of Included Studies. What are Quality Assessment tools?. Randomized Controlled Trials (RCTs). 2024. Available from: https://guides.lib.unc.edu/systematic-reviews/assess-quality . Last accessed on: 07 August 2024.
- De Cassai A, Boscolo A, Zarantonello F, Pettenuzzo T, Sella N, Geraldini F, et al. Enhancing study quality assessment: an in-depth review of risk of bias tools for meta-analysis-a comprehensive guide for anesthesiologists. J Anesth Analg Crit Care. 2023;3(1):44.
- CEBM. Critical Appraisal tools. Randomised Controlled Trials (RCT) Critical Appraisal Sheet. 2024. Available from: https://www.cebm.ox.ac.uk/resources/ebm-tools/critical-appraisal-tools . Last accessed on: 07 August 2024.
- JBI. Checklist for Randomised Controlled trials. 2020. Available from: https://jbi.global/sites/default/files/2020-08/Checklist_for_RCTs.pdf . Last accessed on: 07 August 2024.
- Baker A, Young K, Potter J, Madan I. A review of grading systems for evidence-based guidelines produced by medical specialties. Clin Med (Lond). 2010;10(4):358-63.
- NIH. NHLBI. Study Quality Assessment Tools. 2021. Available from: https://www.nhlbi.nih.gov/health-topics/study-quality-assessment-tools . Last accessed on: 07 August 2024.
Senior Analyst-I, Skyward Analytics
